Motor fuel multipurpose agents



United States Patent 3,527,584 MOTOR FUEL MULTIPURPOSE AGENTS Helen I. Thayer, Oakmont, Pa., assignor to Gulf Research & Development Company, Pittsburgh, Pa., a

corporation of Delaware No Drawing. Filed Apr. 25, 1966, Ser. No. 544,839

Int. Cl. C101 1/26 US. CI. 4458 4 Claims ABSTRACT OF THE DISCLOSURE Motor fuel multipurpose additives comprising ethoxylated or propoxylated 1,2,4- or 1,2,5-trisubstituted imidazolines or the mixtures of lecithin with said imidazolines or the reaction product of lecithin with said imidazolines.

This invention relates to multipurpose additives for motor fuels and to motor fuel compositions containing a minor proportion of said additives. The additives of the present invention perform two primary functions in gasoline including (1) reduction of wear in cast iron piston rings of a gasoline-burning engine and (2) reduction of the tendency of gasoline to clog a fuel filter element. Therefore, this invention also relates to methods for improving the performance of gasoline-burning engines.

The additives of the present invention comprise ethoxylated or propoxylated 1,2,4- or 1,2,5- trisubstituted imidazolines. The additives of the present invention also comprise mixtures of lecithin and ethoxylated or propoxylated 1,2,4- or 1,2,5-trisubstituted imidazolines or the reaction product of lecithin and said imidazolines.

It is surprising that the ethoxylated and propoxylated derivatives of trisubstituted imidazolines are capable of functioning as gasoline antiwear agents. The reason is that while nonalkoxylated disubstituted imidazolines are highly effective gasoline antiwear agents, nonalkoxylated trisubstituted imidazolines are not antiwear agents. However, in accordance with this invention it has been found that the alkoxylation of trisubstituted imidazolines with 1 to 3 mols of ethoxide or propoxicle not only imparts antiwear characteristics thereto but furthermore imparts antiwear characteristics which are considerably superior as compared to the antiwear qualities of nonalkoxylated disubstituted imidazolines. The antiwear characteristics of alkoxylated trisubstituted imidazolines is still more surprising in view of the fact that when disubstituted imidazolines are alkoxylated they lose their antiwear characteristics. The critical distinction in chemical structure of the alkoxylated trisubstituted imidazolines of this invention over closely related alkoxylated and nonalkoxylated amines are set forth in greater detail below in this application and in applications Ser. No. 544,838 and Ser. No. 544,840, each entitled Motor Fuel Multipurpose Agents and filed on the same date as this application by the same inventor.

The imidazolines of this invention have an ethoxylated or propoxylated alkylamine substituent in the 1-position; an alkyl substituent containing 7 to 29 carbon atoms in the 2-position; and one methyl substituent in either the 4- or the 5-position. Although it is invariably expected that the presence or absence of a methyl substituent will be noncritical in a gasoline additive compound, the presence of a single methyl substituent in the 4- or 5- position of the imidazoline ring is critical in the alkoxylated imidazolines of this invention. A preferred trisub stituted imidazoline of this invention is prepared by reacting dipropylene triamine previously reacted with two mols of ethylene oxide with a mixture of saturated and unsaturated fatty acids to produce l-(N-hydroxyethoxyethyl-2-(or 1-)-methyl 2 aminoethyl 2 -long chain alkyl-4(or 5-)-methylimidazoline having the general formula N CH2 c113 or methyl isomers thereof, or the corresponding imidazolines having two separate hydroxyethyl groups attached to the side chain nitrogen.

In the absence of lecithin, the trisubstituted imidazolines of this invention per se impart a beneficial effect when added to gasoline. The trisubstituted imidazolines by themselves impart antiwear properties to gasoline as evidenced by reduction in loss of metallic iron from cast iron piston rings. However, when the trisubstituted imidazolines are either mixed with or reacted with lecithin, the product exerts an additional highly beneficial effect in gasoline, namely, substantial reduction of the tendency of the gasoline to clog the fuel filter element through which it passes in its fiow to an engine. The lecithinirnidazolines of this invention probably reduce filter clogging by completely dissolving some of the dispersed solids in gasoline and by partially dissolving other dispersed solids to reduce the size thereof.

The antifilter-clogging characteristic of the lecithin-containing additives of this invention is highly important because in nearly all automobiles motor fuels are filtered during flow to an engine. Furthermore, reducing the level of solids in gasoline in itself tends to decrease wear of piston rings by reduction of abrasion at said piston rings. Therefore, the antiwear and antifilter-clogging characteristics of the lecithin-imidazoline additives of this invention cooperate to produce a common advantageous effect: the antiwear function contributing directly to piston ring wear rate reduction and the antifilter-clogging function contributing indirectly to reduction of engine wear by completely dissolving a portion of the potentially abrasive solids in gasoline and by partially dissolving another portion of said solids to reduce the size thereof, thereby permitting easier removal of the remaining solids by fil tration.

The antifilter-clogging characteristic of the mixture of or the reaction product of lecithin and the trisubstituted imidazolines of this invention is especially surprising since neither lecithin by itself nor the trisubstituted imidazolines of the invention by themselves impart antifilter-clogging characteristics to gasoline. On the other hand, gasoline compositions containing either the unreacted mixture of or the reaction product of lecithin and the trisubstituted imidazolines of this invention exhibit high antifilter-clogging characteristics.

A significant feature of the present invention is that imidazolines differing from the imidazolines of the present invention only by the omission of the methyl substituents from the imidazoline ring or only by omission of the ethoxyor propoxy-substituent do not exhibit antiwear properties. Therefore, while the trisubstituted imidazoline prepared by reacting fatty acid with dipropylene triamine plus two mols of ethylene oxide and having the formula or the methyl isomers thereof, or the corresponding imidazolines having two separate hydroxyethyl groups attached to the side chain nitrogen, is a highly effective antiwear agent, the disubstituted imidazoline prepared by reacting fatty acid with diethylene triamine plus two mols of ethylene oxide and having the formula or the corresponding imidazoline having two separate hydroxyethyl groups attached to the side chain nitrogen, is not an antiwear agent. Also, while the ethoxylated trisubstituted imidazoline of this invention is a highly effective antiwear agent, the same imidazoline in nonethoxylated form and having the formula or the methyl isomers thereof, is not an antiwear agent. Therefore, the minor modifications of the trisubstituted imidazolines of this invention comprising deletion of the methylsubstituent from the imidazoline ring or deletion of the ethoxy-derived substituent from the side chain nitrogen deprives the imidazoline of its antiwear properties.

The 1,2,4-trisubstituted or 1,2,5-trisubstituted imidazolines of this invention have the general formula wherein R is a saturated or unsaturated hydrocarbon radical containing 7 to 29 carbon atoms, generally, and 11 to 17 carbon atoms, preferably.

R and R are either hydrogen or a methyl radical, with the provision that one is a methyl radical and the other is hydrogen.

R is a methylene, ethylene, or propylene (methylethylene which is either group, and is preferably a propylene group.

R is hydrogen, a methyl, ethyl, hydroxyethyl, hydroxyethoxyethyl, hydroxyethoxyethoxyethyl, hydroxypropyl, hydroxypropoxypropyl or hydroxypropoxypropoxypropyl radical, and

R is hydrogen, a methyl, ethyl, hydroxyethyl, hydroxyethoxyethyl, hydroxyethoxyethoxyethyl, hydroxypropyl, hydroxypropoxypropyl or hydroxypropoxypropoxypropyl radical, with the provision that at least one of said R and R radicals is an hydroxyethyl, hydroxyethoxyethyl, hydroxyethoxyethoxyethyl, hydroxypropyl, hydroxypropoxypropyl or hydroxypropoxypropoxypropyl radical, preferably an hydroxyethoxyethyl radical.

Examples of suitable imidazolines of this invention include 1-(hydroxyethoxyethyl-aminopropylene)-2-(8-heptadecenyl)-4-methylimidazoline; l (hydroxyethylaminomethylethyl)-2-heneicosyl 5 methylimidazoline; l-(N, N-dihydroxypropylaminopropylene) 2 (8',l0-heptadecadienyl) 4 methylimidazoline; 1 (N,N dihydroxyethylaminopropylene) 2 (undecyl)-5- (or 4)-methylimidazoline; 1 (N-hydroxypropoxypropoxypropylaminopropylene) 2 (-8-pentadecenyl)-5-(or'4)-methylimidazolinc; and 1 (N-hydroxyethoxyethoxyethyl)-2-heptadecyl- 4(or 5 -methylimidazoline.

A preferred commercial imidazoline whose major component is N Hz CH:

or the methyl isomers thereof, or the corresponding imidazoline having two separate hydroxyethyl groups attached to the side chain nitrogen, is prepared by reacting a mixture of long chain fatty acids with dipropylenetriamine which has previously been reacted with 2 mols of ethylene oxide. Other imidazolines of this invention can be prepared by reacting a fatty acid having 8 to 20 carbon atoms with N-aminomethylpropylenediamine or N-aminoethylpropylenediamine previously reacted with ethylene oxide or propylene oxide. The fatty acid mixture used in the synthesis of the commercial imidazoline comprised 37.0 percent linoleic acid, 6.0 percent conjugated linoleic acid, 52.5 percent oleic acid, 0.5 percent palmitic acid, 0.5 percent palmitoleic acid, 2.5 percent stearic acid, and 1.0 percent of other acids. Other suitable acids that can be used in the synthesis include lauric, myristic, arachidic, behenic, cerotic, lignoceric and other saturated and unsaturated fatty acids.

Any lecithin can be utilized in accordance with this invention, such as lecithin derived from soybean oil, corn oil, linseed oil or egg yolk. A suitable commercial lecithin to be reacted with or admixed with an imidazoline of this invention is a neutral oil solution of a filtered soybean lecithin with moisture value less than 0.75 percent, an acetone-insoluble value of 70 percent, and a viscosity of 3046 centipoises. According to one method of preparation of the lecithin derivative of the trisubstituted imidazoline, base lecithin is reacted with the imidazoline at 55-80 C. with stirring for a reaction time of from about 19 to 55 hours. The conditions for reaction of the base lecithin with the trisubstituted imidazoline of this invention are not critical. In general, the reaction can occur at a temperature between about 40 and 100 C. for a time duration of about 5 to 100 hours.

The concentration in gasoline of the additives of this invention is not critical. For example, the additives of this invention can be present in gasoline in a general concentration range of 0.1 to 100 pounds per 1000 barrels, or a preferable concentration range of 1 to 25 pounds per 1000 barrels. In terms of weight percentage, the additives can be present in gasoline in a general range of .00004 to .04 percent and a preferable range of .0004 to .01 percent. If the additive to the gasoline comprises an unreacted mixture of lecithin and imidazoline, the components of the mixture can be present in a wide ratio. For example, the ratio of components in the mixture can range from substantially no lecithin to from about 1:100 to about 20:1 weight ratio of lecithin to amine.

The gasoline compositions of this invention contain as the hydrocarbon portion thereof any of the known gasoline hydrocarbons, such as, for example, hydrocarbons boiling in the range of about to 400 or 425 F. The hydrocarbon portion of the gasoline composition can comprise normal, branched-chain, and cyclic hydrocarbons having from 4 to 12 carbon atoms. The gasoline also can comprise products prepared in the chemical conversion of hydrocarbons to produce gasoline. Such conversion products include the products prepared by isomerization, alkylation, polymerization, cracking, disproportionation, hydrogenation, dehydrogenation, and combinations of such processes. A common gasoline composition contains a major proportion of the gasoline hydrocarbons prepared by fluid catalytic cracking and a minor proportion of an alkylate prepared from isobutane and C and/or C olefins. The base fuel can comprise about 80 percent of gasoline from the fluid catalytic-cracking process, and about 20 percent of the aforementioned alkylate.

EXAMPLE 1 A series of tests was performed utilizing radioactive piston rings to compare the gasoline antiwear properties of a disubstituted imidazoline, a nonethoxylated trisubstituted imidazoline and an ethoxylated trisubstituted imidazoline. Following is a description of the procedure that was utilized in these tests.

Test procedure The radioactive ring wear test was performed with a laboratory test, 4-stroke, single cylinder internal combustion engine equipped with a cast iron top compression ring which prior to use had been rendered radioactive by insertion into the pile of an atomic reactor. The engine provided with the radioactive ring was operated at constant speed for hours under the following test conditions:

Speed: r.p.m. 2000 Load: BHP 5 Spark: deg. Air-fuel ratio 13.7/ 1.0 Cylinder wall temp. F. 112 Sump oil temp. F. 125 Carburetor: intake air temp. F. 85

1 Before top center.

During the test the motor oil accumulated particles of the radioactive metal lost by the radioactive piston ring through wear. The radioactive metal content of the motor oil was continuously counted by means of a Geiger counter and recorded. At intervals oil samples were taken and the amount of dilution of oil by fuel was determined. Since dilution of oil by fuel tends to depress the radioactivity measurement, the amount of wear was calculated on the basis of radioactivity counts corrected by a factor corresponding to the amount of dilution of the motor oil with fuel.

The results of the antiwear tests are shown in Table 1.

a A mixture comprising in major proportion (Cm-(I? NCH2(|7HNH2 are and/ or methyl isomers thereof.

b A mixture comprising in major proportion (Cm-(I3 N-CH2 CHNH CII2CHZO)QH N Hz C H3 CH (EH3 and/or methyl isomers thereof, or the corresponding imidazolines having two separate hydroxyethyl groups attached to the side chain nitrogen.

Table 1 shows that while a disubstituted nonethoxylated imidazoline is a highly effective antiwear agent, a nonethoxylated trisubstituted imidazoline is not an antiwear agent. However, Table 1 further shows that ethoxylation of the trisubstituted imidazoline not only converted it into an antiwear agent but produced an antiwear agent superior to the disubstituted imidazoline. This showing is especially surprising in view of the showing in Example 2 that ethoxylation of the disubstituted imidazoline caused loss of antiwear properties.

EXAMPLE 2 Table 2 shows the results of radioactive piston ring wear tests conducted with a base motor oil to determine the antiwear properties of disubstituted and trisubstituted imidazolines in both the ethoxylated and nonethoxylated states.

TABLE 2.RADIOACTIVE PISTON RING WEAR TESTS Concen- Control tration iron wear Fuel additive (p.p.m.) Piston rings Oil (mg) Test iron wear (mg.) The reaction product of long chain fatty acids and 98.5 Radioactive Base motor oil free 8.7 6.1

diethylene triamine. cast iron. of additives. The reaction product of long chain fatty acids with 98. 5 ...do d0 8. 7 No significant change in wear as diethylene triamine and 2 mols of ethylene oxide compared to control. The reaction product of long chain fatty acids with 98 5 do .do 5. 5 4.3

dipropylene triaminc plus 2 mols of ethylene oxide. e The reaction product of long chain fatty acids and 98 5 do do 5. 5 No significant change in wear dipropylene triarnine.

as compared to the control.

a A commercial mixture comprising about to percent by weight of 1-(Z-aminoethyl)-2-hcptadccenylimidazoline:

(Ci7)CNCH2CHzNH2 II N /C H2 CH2 and/or corresponding imidazolines having two separate hydroxyethyl groups attached to the side chain nitrogen.

and/or methyl isomers thereof, or corresponding imidazolines having two separate hydroxyethyl groups attached to the side chain nitrogen.

CH Hs and/or methyl isomers thereof.

CHa

7 8 As shown in Table 2, the disubstituted imidazoline is Spark advance: deg. 1 38:3 a highly effective antiwear agent but ethoxylation there- Spark plug gap: in. 0.040 of causes it to lose its antiwear properties. Therefore, it Valve clearances: in.: would not be expected that ethoxylation could impart Intake 0.008 antiwear properties to a closely related imidazoline com- Exhaust 0.013 pound. But, surprisingly, the table shows that trisubsti- Intake manifold tuted imidazoline is not an antiwear agent but ethoxyla- Pistons tion imparts antiwear properties thereto. Water jacket coolant temperature:

Inlet: F. 85+5 EXAMPLE 3 l Outlet: 0 F- A further series of tests was conducted which utilized oil temperature; F 155:5 a method other than radioactivity to determine both anti- Ai --fuel ratio 14 5 0 5 1 wear characteristics and engine cleanliness characteristics crankcase il i f m 1 of a gasoline sample containing an ethoxylated trisubsti- 011 h qt 41 tuted imidazoline of this invention and a gasoline sample 15 crankcase lubricant Motor Oil containing a nonethoxylated disubstituted antiwear agent. 1 Before top center at 2500 mum The antiwear tests measured the individual wear rate of 2 Heat control locked in 005" position, each of the three piston rings of each of the six cylinders T111 Plated cast trollin an automobile engine. The following procedure was At the end of the test, the engine is disassembled and utilized for conducting the tests of this example. rated visually for deposits on the following parts to es- Test procadure tablrsh the total engine cleanliness rating.

The test is performed with a 216 cu. in. 6-cylinder auto- Varnish deposits: Sludge deposits mobile engine in five 8-hour test periods. Following each Piston skirts Oil screen. of the first four periods of operation the engine is shut Cylinder walls Crankcase oil pan. down for a 4-hour interval. Preceding the first 8-hour Crankcase oil pan Rocker-arm assembly. test period there is a progressive break-in over a 4-hour Push-rod cover plate Rocker-arm cover plate. period in order to reach test conditions by the end of Rocker-arm cover plate Push-rod cover plate. the last hour of the break-in period. At the end of the break-in period the crankcase oil is drained, the crankcase The total engme 'f is the Sum of e a ngs made refilled and the engine operated for a 10-minute warm-up 0n the ten Part5 listed above- Each P is rated 011 8 before commencing the first 8-hour period of test opera- 86816 f 0 l Y deposits) to 10 i The piston rings were weighed before and after the Following are the conditions prevailing during the test: test o ascertain the ring Wcl'ght 105$- Load. BHP :1 35 The results of the tests of this example are shown in Speed: r.p.m. 2500:25 Table 3.

TABLE 3.EFFECT 0F nDDlTn i g gN ENGINE CLEANLINESS AND Fuel make-up: percent by volume, ga oline 100 100 100 100 Added:

Tetraethyl lead, mL/gal 2.5 2.5 2.5 2.5 The reaction product of long chain fatty acids and diethylene triaminemlbs/1,000 b 25 The reaction product of long chain fatty acids with dipropylene triamine plus 2 mols ethylene oxide, lbs 1,000 b 25 Oil make-up, percent by volume:

Light neutral oil 30.25 30. 25 30. 25 30. 25 Medium neutral oil 65.00 65.00 65.00 65.00 on additive a 4. 25 4.25 4. 25 4.25 on additive 0.50 0.50 0.50 0.50 Oil additive 0.01 0.01 0. 01 0. 01 G-cylinder automobile engine cleanliness and wear test:

Total engine cleanliness rating (100=clean) (varnish -and sludge) 80.0 82.0 81.0 85.5 Skirt varnish rating, avg. piston (l0= clean) 6. 5 7. 5 7. 0 7. 5 Ring weight loss:

First ring (compression), average weight loss for six pistons, mg 92 I68 74 1 44 Second ring, average weight loss for six pistons, mg- 34 I 30 35 t 18 Third ring, average weight loss for six pistons, mg-.. 54 l 34 38 6 27 Total average ring weight loss, mg 180 1 132 147 89 a A commercial mixture comprising about 90 to percent by weight of 1-(2-aminoethy1)- 2-heptadecenylimidazollne:

h A mixture comprising in major proportion Ha H:

and/or methyl isomers thereof or corresponding imidazolines having two separtae hydroxy' ethyl groups attached to the side chain nitrogen.

e Commercial antioxidant, bearing corrosion inhibitor and detergent comprising barium sulfonate, barium phosphonate, zinc dialkyl dithiophosphate and a nitrogen-containing compound.

Table 3 shows that the ethoxylated trisubstituted im- Table 4 shows that in the absence of lecithin, an idazoline of this invention achieved a total average reducethoxylated trisubstituted imidazoline of this invention tion in piston ring wear of 40 percent as compared to a does not have a favorable effect upon gasoline filter-clogtotal average reduction in piston ring wear of 27 percent ging characteristics. for the disubstituted imidazoline antiwear agent. Table 3 5 also shows the high utility of an additive of this invention EXAMPLE 5 m ir ri m iil s a iril zlilii v tz he results of tests conducted A further Series of gasoline filter'clogging tests was to illustrate the improvement imparted to gasoline by conducted to illustrate the improvement imparted to gasolecithin mixtures with ethoxylated trisubstituted imidazohne by leclthm mlxtures Wnh and denvatlves of alkoxyl' line and lecithin derivatives of ethoxylated trisubstituted i g i f ofrthis invelntion' i f imidazoline in regard to gasoline filter-clogging characteres W? P W1 a gaso 6 cqntiumng istica a leclthin m xture with ethoxylated trisubstituted imldazo- EXAMPLE 4 line, and with a gasoline sample containing a lecithin derivative of ethoxylated trisubstituted imidazoline. The results of these tests are shown in Table 5. In interpreting the results of Table 5, it is noted that a gasoline is cong free of lecithin The gasoline circulation tests sidered to exhibit satisfactory filter-clogging characteristermined the total gasoline throughput through a fuel tics when there is less than 50 percent reduction 1n fuel filter element required to produce a 50 percent reduction flow rate through a filter.e1ementat20 gan0n throughput in flow rate through the filter lement As noted above, satisfactory filter-clogging performance 1s achieved when there is less than 50 percent re- TABLE 4 GASOLINE. CIRCULATION TESTS duction in fuel flow rate through a filter element at 20 gi gl l rakeup: perc y volume, gasoline 100 1 gallons throughput. The data in Table 4 indicated that Tetraethyl lead: mL/gal 3,0 3,0 ethoxylated trisubstituted irnidazoline without lecithin did 100/2 Texas oil: percent by volume Table 4 shows the results of gasoline circulation tests 15 made with gasoline samples with and without an ethoxylated trisubstituted imidazoline, both gasoline samples be- Solventoi]; percent by volume not produce a gasoline composition meeting this filter- Tlzie reactipn p'qducit of 11ong2cha1in gatttgr {acids aid clOgging performance requirement. AlSO, Table 5 SllOWS 1 1'0 @118 T1311) I16 US mo S0 e eneoxi (5 lbs/1 00(l l bls .2 15 that lecithin W1th0ut ethoxylated trisubstituted IIIIIdaZO- Circulation test fuel throughput in gallons until there isa50percentreductioninflow ratethrough fi1ter 20 5 hne dld not produce a gasolme composmon meetlng thls filter-clogging performance requirement. However, Table 5 shows that both the mixture of lecithin with ethoxylated a A mixture comprising in major proportion fi N'O1'I2 CHNH(CH2OH20)2H trisubstituted imidazoline and the lecithin derivative of N CH2 CH: ethoxylated trisubstituted imidazoline produced a gasoline on composition which easily satisfied required performance e levels. Table 5 also shows that use of both the mixture and/OT methyl isomers thereof, or corresponding imldazounes having two of lecithin wlth ethoxylated t risubstituted 1m1dazol1ne and separate hydroxyethyl groups attached to the side chain nitrogen. the derivative of leclthln Wlth ethoxylated trisubstituted and Additives in Gasoline to Clogging of Filters in Automotive Fuel 40 type gum deposites a o par d t th Performance f a1 L gg siltafighuparregerigtlegat Philadelp 1a, Pennsylvani Meeting October 16 clthm a1 0 n e m thls regard TABLE 5.GASOLINE CIRCULATION TESTS Gasoline additives:

Lecithin n X Reaction product of lecithin and the reaction product of long chain fatty acids and dipropylene triamine plus 2 mols of ethylene oxide b X Mixture of lecithin I and the reaction product of long chain fatty acids and dipropylene triarnine plus 2 mols of ethylene oxide b X Gasoline tests:

Gasoline Circulation Test percent reduction in flow rate at stated fuel throughput (more than percent reduction in flow rate at 20 gallons fuel throughput is unsatisfactory) (1) 2) (s) Intake System Deposit Test percent reduction in carburetor-type gum deposits 46 5g 5 A commercial neutral oil solution of a filtered soybean lecithin with moisture value less than 0.75 percent by weight, an acetone-insoluble value of percent by weight and a viscosity of 3,046 centipoises.

b A mixture comprising in major proportion N\ Hz (.1113

C H CH and/or methyl isomers thereof, or corresponding imidazolines having two separate hydroxyethyl groups attached to the side chain nitrogen.

e For the Gasoline Circulation Tests additive concentrations were 15 lbs. per 1,000 barrels of gasoline plus 0.5 percent by volume solvent oil. Gasoline Circulation Test procedure is described in SAE Reprint No. 610 B, G. E. Gaston and J. J. Thomas, "Contribution of Sediment and Additives in Gas line to Clogging of Filters in Automotive Fuel Systems, presented at Philadelphia, Pennsylvania, Meetings, October 29-November 2, 1962.

d For the Intake System Deposit Tests the concentration of additives was 15 lbs. per 1,000 barrels of gasoline. The test similates deposition of gum carried by gasoline in a carburetor and involves forming a gum deposit in a test apparatus by evaporating additive-containing, high gum content fuel flowing countercurrent to a stream of heated air. At the end of the test, the Weight of the adhering gum is determined and compared to a reference run without additive for an appraisal of the additives detergency action. The test employs the same apparatus described by J. L. Keller and F. S. Liggett, Induction System Gum-Engine Versus Bench Test, Symposium on Vapor Phase Oxidation of Gasoline, ASTM Special Technical Publication No. 202, pp. 21-40 (1956), but a somewhat difierent procedure is employed in order to appraise detergency action of additives. A gum deposit is formed on the walls of a steam-jacketed glass U-tube by evaporating two liters of gasoline distillate admitted to the system countercurrent to a stream of preheated air. The U-tube is then washed with a number of ortions of naphtha until a final wash shows no discoloration. The amount of gum adhering to the apparatus is then determined by extracting with C. acetone and evaporating the acetone extract with filtered, heated air to obtain a gum residue which is heated in an oven for one-half hour at 105 0., cooled and Weighed. Results of runs using the same gasoline with and without additive are compared to determine detergency action.

1 50 percent at 10-15 gallons.

2 35 percent at 20 gallons.

8 20 percent at 20 gallons.

Various changes and modifications can be made without departing from the spirit of this invention or the scope thereof as defined in the following claims.

I claim:

1. A motor fuel comprising gasoline and between about .00004 and .04 percent of a trisubstituted imidazoline having the formula wherein R is an alkyl radical containing 7 to 29 carbon atoms, R and R are either hydrogen or a methyl radical, with the provision that one is a methyl radical and the other is hydrogen, R is a methylene, ethylene, or propylene group and R and R are selected from the group consisting of hydrogen, methyl, ethyl, hydroxyethyl, hydroxyethoxyethyl, hydroxyethoxyethoxyethyl, hydroxypropyl, hydroxypropoxypropyl and hydroxypropoxypropoxypropyl, with the provision that at least one of said R and R radicals is an hydroxyethyl, hydroxyethoxyethyl, hydroxyethoxyethoxyethyl, hydroxypropyl, hydroxypropoxypropyl, or hydroxypropoxypropoxpropyl radical.

12 .00004 and .04 percent of a trisubstituted imidazoline having the formula IUI\ H-Ra wherein R is an alkyl radical containing 7 to 29 carbon atoms, R and R are either hydrogen or a methyl radical, with the provision that one is a methyl radical and the other is hydrogen, and

R is a propylene group.

4. A motor fuel comprising gasoline and between about .00004 and .04 percent of a lecithin derivative of or mixture with a trisubstituted imidazoline of claim 3.

References Cited UNITED STATES PATENTS 2,633,146 3/1953 Witt 123-436 2,773,492 12/ 1956 Klemm 123136 2,987,527 6/1961 Sincroft et al. 44--66 3,014,793 12/1961 Weisgerber et al. 44-66 3,131,751 5/1964 Twibell 123136 3,273,980 9/1966 Le Suer et al. 4463 3,282,836 11/1966 Miller et al. 4463 DANIEL E. WYMAN, Primary Examiner 2. A motor fuel comprising gasoline and between about 30 Y H. SMITH Assistant Examiner .00004 and .04 percent of a lecithin derivative of or mixture with a trisubstituted imidazoline of claim 1.

3. A motor fuel comprising gasoline and between about US. Cl. X.R. 44-63, 76

\ gz g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION pe 3,527,584 Dated September a, 1970 Inventor(s) Helen I. Thayer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 19, "20" should read 30--.

Table 3, under footnote 5, "34 percent" should read -37 percent-.

Table 4, line 28, appearing at the beginning of the line should appear at the end of the line after "ethylene oxide".

Signed and sealed this 3rd day of August 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

